This disclosure describes, in one aspect, a composition that includes a ²-glucan component and an antibody component that specifically binds to the ²-glucan. In another aspect, this disclosure describes a method of increasing a subject's response to ²-glucan immunotherapy. Generally, the method includes identifying the subject as a low binder of ²-glucan and administering to the subject a composition that comprises a ²-glucan moiety conjugated to the therapeutic antibody. In some cases, the therapeutic antibody can be an anti-tumor antibody.